Hydrovac trucks include a water tank, water wand connected to the water tank and water pump connected to pump water from the water tank to the water wand, mud tank, vacuum hose with dig tube connected to the mud tank, and blower to blow air from the mud tank and cause a negative pressure that draws material from the vacuum hose, as well as associated controls and drives. Water jets from the water wand are used to dig in soils, which creates a slurry, and the blower causes a vacuum in the mud tank that enables the dig tube to draw the slurry into the mud tank. Regulations limit weight on wheels of hydrovac trucks.
In addition, vibration from a hydrovac engine can cause maintenance issues for driving a hydrovac blower using a gear train.